'History of the City of Rome in the Middle Ages' originally published in 8 vols, London: G. Bell, 1894-1902. - Translation of 'Geschichte der Stadt Rom im Mittelalter' 4.Aufl. Stuttgart: J.G. Cotta 1889? - 1903.
Rome and medieval culture : selections from 'History of the City of Rome in the Middle Ages' by Ferdinand Gregorovius. ISBN 0226307492. Published by University of Chicago Press in 1971. Publication and catalogue information, links to buy online and reader comments.